The Hosmer Branch Library was built in 1910 on Gratiot Avenue and Pulford Streets. Named for George S. Hosmer, the branch had previously been located in a school in 1900 and then a temporary building on Gratiot in 1903 The Italian Renaissance structure was designed by Louis Kamper, and cost $24,543 to build. It formally opened in January of 1911, and featured adult and children's reading rooms, club room, and a 200-seat auditorium in the basement.
Hosmer Branch closed on May 30th, 1932, and the building was turned over to the Board of Health. When Gratiot Avenue was widened in 1936, the building was moved back from the street. After leasing the former library for 13 years, the health department bought the building in 1945. It served in various health-related capacities, eventually becoming an HIV clinic run by the Department of Human Services. It closed sometime after 2007, and was abandoned.
Much of the interior of the building was destroyed by a suspicious early morning fire on April 21st, 2016. Despite the heavy damage, the building was sold to a developer in September of 2016 who intends to convert it into a book store and cafe. It was renovated in 2022 and is now used by Macro Connect, an IT consulting firm.